title: Consequence of one-electron oxidation and one-electron reduction for aniline.
abstract: Quantum-chemical calculations were performed for all possible isomers of neutral aniline and its redox forms, and intramolecular proton-transfer (prototropy) accompanied by π-electron delocalization was analyzed. One-electron oxidation (PhNH(2) - e → [PhNH(2)](+•)) has no important effect on tautomeric preferences. The enamine tautomer is preferred for oxidized aniline similarly as for the neutral molecule. Dramatical changes take place when proceeding from neutral to reduced aniline. One-electron reduction (PhNH(2) + e → [PhNH(2)](-•)) favors the imine tautomer. Independently on the state of oxidation, π- and n-electrons are more delocalized for the enamine than imine tautomers. The change of the tautomeric preferences for reduced aniline may partially explain the origin of the CH tautomers for reduced nucleobases (cytosine, adenine, and guanine).
authors.affiliation: Department of Chemistry, Warsaw University of Life Sciences (SGGW), ul. Nowoursynowska 159c, 02-776 Warszawa, Poland. ewa_raczynska@sggw.pl
authors.forename: Ewa D
authors.initials: ED
authors.lastname: Raczyńska
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Stępniewski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kolczyńska
mesh_terms: D000225:Adenine / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry*; D002625:Chemistry, Organic; D003596:Cytosine / Q000737:chemistry; D004583:Electrons; D006147:Guanine / Q000737:chemistry; D007097:Imines / Q000737:chemistry; D007536:Isomerism; D018716:Molecular Mimicry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D000814:Aniline Compounds; D007097:Imines; D006147:Guanine; D003596:Cytosine; D000225:Adenine; C023650:aniline